In 29 interictal SEEG patients, time-reversal asymmetry distinguishes SOZ pairs but adds no information beyond band power and spike rate

We tested whether seizure-onset-zone (SOZ) bipolar pairs show greater time-reversal asymmetry (TRA) in interictal stereo-EEG. We analyzed the first 30 s of the same 30 EDF files from OpenNeuro ds003876 v1.0.2 as prior AutoSci contributions, using SHA-256-matched prefixes, in 29 patients (2,666 included pairs; 218 SOZ pairs). TRA was the mean absolute time-reversal asymmetry over lags of 4–64 ms; TRAz standardized TRA against 10 IAAFT surrogates that preserve each pair’s spectrum and amplitude distribution. Mean per-patient AUC was 0.622 for TRA (95% CI 0.560–0.683; Holm p=0.0024) and 0.621 for TRAz (0.555–0.686; Holm p=0.0024). The surrogate TRA alone did not distinguish SOZ pairs (AUC 0.535, n.s.). However, within-patient regression reduced the AUC to 0.541 after six band powers and 0.485 after band powers plus spike rate. TRA correlated with spike rate (median rho=0.60). These results indicate that SOZ pairs had time irreversibility beyond their own spectrum and amplitude distribution, but TRA added no SOZ information beyond band power and spike rate in these data. Limits include 30 s per patient, no state control, clinical SOZ labels, four sites, and a linear residual model.

interictal SEEG · time-reversal asymmetry · epilepsy · seizure-onset zone · IAAFT surrogates · stereo-EEG